With the advancement of mobile telecommunication services, it has become significantly easier to contact people, whether at home, at work, or elsewhere. Even though society has transformed from a society without mobile communications to one where a majority of people carry a mobile telephone at all times, there are many reasons why someone with a mobile telephone would not know that someone is calling the mobile telephone despite having the mobile telephone with him or her. For example, someone with a mobile telephone in his or her pocket might have the mobile telephone on a low volume or “beep” ring due to being recently at work and not hear the mobile telephone ring. As another example, a woman who has her telephone in her purse might not hear the mobile telephone ringing or feel vibration of the mobile telephone. Many other examples could additionally be provided to show that a user of a mobile telephone is not always aware that his or her mobile telephone is ringing.
In the event of a emergency, a caller who is attempting to reach someone with a mobile telephone who is not answering the mobile telephone for any reason has few, if any, options to reach the person if the person being called is away from work, home, or other easily reachable location (e.g., hotel). Unless the caller has a telephone number of another person who might be with the person the caller is attempting to reach, the caller has to wait for the person to check his or her telephone to see that the caller has been attempting to reach the person. In an emergency or other important situation, any delay in contacting someone may be too long.